package com.huahan.auth.Utils;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;

/**
 * @author dd
 */
public class IpUtils {

  public static final String UNKNOWN = "unknown";
  public static final int LENGTH = 15;
  private static final Logger logger = LoggerFactory.getLogger(IpUtils.class);

  /**
   * 获取IP地址 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，
   * X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
   */
  public static String getIpAddress() {
    String ip = null;
    try {
      HttpServletRequest request =
          ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
      ip = request.getHeader("x-forwarded-for");
      if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getHeader("Proxy-Client-IP");
      }
      if (StringUtils.isEmpty(ip) || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getHeader("WL-Proxy-Client-IP");
      }
      if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getHeader("HTTP_CLIENT_IP");
      }
      if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getHeader("HTTP_X_FORWARDED_FOR");
      }
      if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getRemoteAddr();
      }
    } catch (Exception e) {
      logger.error("IpUtils ERROR ", e);
    }
    // 使用代理，则获取第一个IP地址
    if (StringUtils.isNotEmpty(ip) && ip.length() > LENGTH) {
      if (ip.indexOf(",") > 0) {
        ip = ip.substring(0, ip.indexOf(","));
      }
    }
    return ip;
  }
}
